From DE 197 09 852 C2 a drive unit of this kind for adjusting seats is known. A motor drives an input gear stage which, in turn, drives a planetary gear as an output gear stage. The output wheel which is configured as a hollow wheel has in its center an out-of-round perforation in which a molded part, which is connected in a rota-tionally rigid manner with a shaft, engages with a positive fit, such shaft being aligned with the drive output wheel.